Fixing device comprising a rotary drive for a gripper tool

ABSTRACT

A device for fixing and rotationally driving a gripper tool or the like on the arm of a crane, an excavator or a similar transporting and lifting machine is disclosed. The device includes a housing. An adapter plate including an annular flange is arranged on the housing, the flange being rotatable about the housing by a grooved ball bearing. The housing includes a hydromotor which transmits the rotational movement thereof to the adapter plate by an output flange. The output flange and the adapter plate are axially distanced from each other. Screw bolts transfer the rotary driving force between the output flange and the adapter plate.

BACKGROUND OF THE INVENTION

The invention relates to a device for attaching and for rotary drive of a gripping tool or the like on the boom of a crane, excavator, or a similar conveying and lifting machine, with a housing attached to the boom, the housing receives in its interior a hydromotor with a driven flange and on the side of the gripping tool has an adapter plate that is for attaching the gripping tool and is driven to rotate by the driven flange.

Such a device is known from the operational practice of Applicant. It is schematically illustrated in the exemplary embodiment in FIG. 1. In accordance with it, the device has a housing 1 that is made of the parts 2 a, 2 b, and 2 c bolted together. A hydromotor 12 is inserted rotation-fast in this housing. The hydromotor is driven by a hydraulic fluid that is conducted into and out of the interior of the hydromotor via lines (not shown). The shaft of the hydromotor generally performs only short rotating movements that rotate a driven flange about a certain degree of angle. An adapter plate 5 is bolted to the driven flange. The adapter plate is placed against the end face of the driven flange 13 on the one hand, and on the other hand it can also be in contact with the end face of the housing part 2 c. In the practical operation, the housing 1 is attached by moans of its upper housing part 2 a to the boom of the crane, excavator, or a similar conveying and lifting machine. The gripping tool 5 is attached to the adapter plate.

During operation of the crane, excavator, or the like, the gripping tool can be moved via the hydromotor 12 to the most suitable angle position via the driven flange 13 and the adapter plate 5. At the same time, additional hydraulic lines (not shown) are present that cause the gripping tool to open and close. The gripping tool now takes hold of construction materials, debris, soil, or the like and conveys it to another location when the boom pivots. It can happen that the gripping tool strikes the ground, a building wall, or the like very hard. The gripping tool is generally operated under the very rough conditions. As long as such an impact occurs strictly in the axial direction of the hydromotor and the housing, there is no problem. However, it is dangerous when impacts also have a radial component so that the housing twists and the motor located therein is stressed in a jarring manner in the oblique direction. It must be remembered that the gripping tool is connected to the shaft of the hydromotor via the adapter plate 5 and the driven flange 13. Since the adapter plate is not fixed in the radial direction, impacts that occur in the oblique direction are ultimately passed on to the shaft of the hydromotor. Over time, this leads to overstressing of the hydromotor and its bearing. Given the usual rough operation of the gripping tool, the consequence over time is damage to or destruction of the hydromotor.

BRIEF SUMMARY OF THE INVENTION

The object of the invention is to embody the device of the type cited in the foregoing such that a long service life is assured for the hydromotor during rough continuous operation with impact-like stresses to the adapter plate in changing directions.

This object is inventively attained in a device of the type cited in the foregoing in that the adapter plate is rotatably borne and radially supported on the housing and is situated at an axial distance from the driven flange.

Thus from a static point of view the inventive solution is a complete departure from the known design. That is, the adapter plate is borne on the housing of the device and thus is fixed and supported radially. The purpose of the driven flange now is more for causing the adapter plate to move rotationally. Impacts that act on the adapter plate in the oblique direction are conducted from outside into the stable housing and are safely absorbed there. But the impacts cannot be passed on to the shaft of the hydromotor because the driven flange and the adapter plate are no longer flush against one another but rather are situated at an axial distance from one another. In contrast to the known design, therefore, the hydromotor can be of lighter construction. Yet a substantially increased service life is attained for the hydromotor.

One advantageous embodiment of the inventive device is comprised in that the housing and the adapter plate are designed in the shape of a bell and engage in one another. In this embodiment, the non-positive fit between the adapter plate and the housing is attained with particular certainty. Furthermore, the housing and the bell-shaped adapter plate mutually reinforce one another by engaging one another so that the housing is clearly stiffened overall.

In terms of design, the latter embodiment can be realized in that the adapter plate is provided with an annular flange that exteriorly encloses the housing. The annular flange thus assumes the function of bearing the adapter plate on the housing.

This bearing is advantageously performed in accordance with another embodiment in that a deep-groove ball bearing is provided between the exterior circumference of the housing and the interior circumference of the annular flange. Given the relatively large diameter of the housing and the annular flange that encircle the hydromotor, the deep-groove ball bearing can be very heavily stressed, even if the balls in the bearing are not very large.

Statically, it is particularly advantageous when the annular flange and the adapter plate are embodied as a single piece. However, cost-effective production is possible when the annular flange and the adapter plate are separate plates and are bolted together.

The axial extension of the entire device can be reduced when in accordance with another advantageous embodiment the driven flange is received in a depression on the inside of the adapter plate.

As stated already, it is sufficient when the driven flange and the adapter plate are only joined to one another as is necessary to attain a common rotational movement. For this purpose, means for positive-fit rotational carrying are provided between the driven flange and the adapter plate.

In practice, the rotational carrying occurs using screw bolts through the driven flange and the adapter plate.

BRIEF DESCRIPTION OF THE DRAWINGS

Accompanying the specification are figures which assist in illustrating the embodiments of the invention, in which:

FIG. 1 illustrates a device in accordance with the prior art; and

FIG. 2 is the inventive device.

DETAILED DESCRIPTION OF THE INVENTION

As has already been stated in the foregoing, a device for attaching and for rotary drive of a gripping tool or the like has a housing 1 that is constructed from the annular housing parts 2 a, 2 b, and 2 c. These housing parts are securely bolted to one another. A hydromotor 12 is inserted rotation-fast in the housing and attached using means that are not shown. The hydromotor drives a driven flange 13 that itself is bolted to an adapter plate 5. In this device known from the prior art the driven flange 13 and the adapter plate 5 are flush against one another. However, depending on installation tolerances, the adapter plate 5 can also be in contact with the end face of the housing part 2.

This device is attached by means of the housing part 2 a to the boom of a crane, excavator, or similar conveying and lifting machine. Thus, the adapter plate 5 carries the gripping tool and causes it to move rotationally for working as soon as the hydromotor 12 is actuated.

The known device can absorb impacts coming from the gripping tool relatively well as long as they are strictly in the axial direction. In this case, the adapter plate 5 sits on the end face of the housing part 2 c so that the hydromotor 12 is not excessively stressed thereby.

However, the situation is different if the impacts that occur unavoidably during operation also have a radial component, that is, the stress of the impact also occurs in the oblique direction. Then the adapter plate 5 slides on the end face of the housing part 2 c and causes flexural stress and impact load on the shaft of the hydromotor 12 because the stress is passed on from the adapter plate 5 via the driven flange 13 to the motor shaft. Furthermore, the entire housing twists. Over time, this necessarily leads to damage to or even destruction of the hydromotor and its bearing.

FIG. 2 illustrates the inventive device. Here, as well, there is a housing 1, which in this case is constructed from the two housing parts 2 a and 2 b. The housing pats are joined to one another using housing bolts 3. Bolt holes are labeled 4; they are used for attaching the housing 1 to the boom of a crane, excavator, or similar conveying and lifting machine.

The lower housing part 2 b is surrounded by an annular flange 6 that is itself bolted to an adapter plate 5 via connecting bolts 7. Provided between the housing 2 b and the annular flange 6 is a deep-groove ball bearing, indicated by the balls 8. Therefore, also located between the lower housing part 2 b and the annular flange 6 is a gap 9 that is covered by the sealing lips 10 and 11. In this manner the deep-groove ball bearing is protected from contamination.

A hydromotor is labeled 12; it is inserted rotation-fast in the housing. The hydromotor 12, via its shaft, drives a driven flange 13 that itself is coupled rotation-fast to the adapter plate 5. There is an axial distance 14 between the driven flange 13 and the adapter plate 5. Screw-bolts are labeled 15; they are means for positive-fit rotational carrying between the driven flange and the adapter plate. As can be seen, the driven flange 13 is received in a depression 18 of the adapter plate 5, saving axial structure length.

The adapter plate 5 and the annular flange 6 form a rigid structural unit that is produced from two parts for cost efficiency reasons only.

For precise centering, there is a centering collar 16 on the adapter plate and a recess 17 in the annular flange 6.

The adapter plate 5 with its annular flange 6 is rotationally arranged on the housing 1, but statically with the latter forms a unit. During rough operation of the gripping tool, any impacts in the oblique direction that occur on the adapter plate 5 are immediately passed on via the deep-groove ball bearing to the massively embodied housing 1. The hydromotor, which has an axial distance 14 from the adapter plate 5, is largely unaffected thereby.

In this manner lightly-constructed hydromotors can be used that still attain substantially longer problem-free operation compared to the prior art and have a longer service life.

The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not as restrictive. The scope of the invention is, therefore, indicated by the appended claims and their combination in whole or in part rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope. 

1-8. (canceled)
 9. A connecting device comprising: an axially extending housing and a motor disposed within the housing; a flange rotatably connecting to the motor, said motor driving said flange so that said flange rotates adjacent to and relative to said housing and said motor; an adapter plate connecting to said flange so that said adaptor plate rotates with said flange; said adapter plate being radially supported on said housing; and said adapter plate being axially spaced from said flange.
 10. The device of claim 9, wherein said housing engages said adapter plate, said housing and said adaptor plate forming the shape of a bell.
 11. The device of claim 10, wherein said adapter plate includes a second flange, said second flange being an annular flange exteriorly enclosing said housing.
 12. The device of claim 11, further comprising a deep-groove ball bearing disposed between an exterior circumference of said housing and an interior circumference of said annular flange.
 13. The device of claim 11 or 12, wherein said annular flange and said adapter plate are bolted to one another.
 14. The device of claim 9 wherein said motor is a hydromotor.
 15. The device of claim 9 rotationally connecting gripping tool to a boom of a lifting machine.
 16. The device of claim 15 wherein said lifting machine is a crane or an excavator. 